The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingRemoval
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove front seat assembly lh
Remove the front seat.
For manual sea ...
Cleaning and protecting
the vehicle exterior
Perform the following to protect the vehicle and maintain it in
prime condition:
Working from top to bottom, liberally apply water to the vehicle
body, wheel wells and underside of the vehicle to remove any dirt
and dust.
Wash the vehicle body using a sponge or soft cloth, such as a
cha ...
Headlight assembly
Components
Removal
Hint:
Use the same procedures for the rh and lh sides.
The procedures listed below are for the lh side.
Disconnect cable from negative battery
terminal
Remove front fender liner lh (see page et-4)
Remove front fender liner rh (see page et-4)
Remove ra ...